public class TestClass: DependencyObject
{
		public static readonly DependencyProperty PropNameProperty = 
			DependencyProperty.RegisterAttached(
				"PropName", 
				typeof(object), 
				typeof(TestClass), 
				new FrameworkPropertyMetadata(null, PropertyChangedCallback));

		private static void PropertyChangedCallback(
				DependencyObject dependencyObject, 
				DependencyPropertyChangedEventArgs args)
		{
			FrameworkElement fe = dependencyObject as FrameworkElement;
			if (fe == null) return;
                        // property was assigned/removed from FrameworkElement
			// so we can do something useful here
		}

	        public static object GetPropName(UIElement element)
		{
			return element.GetValue(PropNameProperty);
		}

		public static void SetPropName(UIElement element, object value)
		{
			element.SetValue(PropNameProperty, value);
		}
}